Whatever they may lack in coding ability and innovation, thankfully eroge publishers can be counted on for fine artwork and fastidious (if not obsessive) observance of the New Year and 1st of April – as proven gamely by these brands:

Why would you get arrested? These illustrations don’t even involve sex.
If you think you would get arrested for this, then how about walking on the street, and accidentally looking at a child?
This is basically the same thing.

On a different note, those underaged looking girls on these illustrations are the best, hands down.